A motor for a train includes a cooling blower for suppressing a heat generation of a rotor of the motor. Therefore, when a suction port of the blower is clogged, because the cooling efficiency becomes insufficient, the temperature of the rotor of the motor rises, an insulation breakdown of the rotor occurs, and the motor malfunctions in some cases. Accordingly, it is necessary to detect an abnormal temperature rise of a stator or a rotor of a motor that is caused by clogging of a suction port of a blower so as to stop an operation of an inverter, thereby preventing the motor from malfunctioning.
For example, as a conventional technology, Patent Literature 1 mentioned below discloses a method of calculating a temperature of a rotor of an induction motor based on slipping and a current of the motor.